1. Field of the Invention
This invention relates generally to guards for the knees and elbows such as are used in contact sports and particularly to a knee guard with a removable shell.
2. Prior Art and Information Disclosure
Injuries to the knees and elbows occur all too frequently in sports such as mountain biking, snow boarding, skate boarding and especially in roller skating and in-line skating. Participants in team sports such as hockey, football, and baseball are also prone to injuries to the joints and limbs. Current growth of in-line skating has heightened interest in ways to reduce injury when participating in these activities. Therefore a number of protective devices have been disclosed which are intended to prevent injury from blows to these areas.
U.S. Pat. No. 3,945,046 to Stroingmn discloses a flexible knee support including a tubular sheath extending around the back of the leg but not covering the knee with broad elastic bands around the leg, one above and one below the knee. The device is intended to support the knee joint rather than protect the knee cap area.
U.S. Pat. No. 3,945,047 is a knee protector including a rubberlike sleeve in which the back of the knee is exposed to provide some degree of flexibility. A compartment over the knee cap is fillable with a fluid for cushioning. Side compartments receive hinged panels for support of the knee joint. The device is suitable for orthopedic uses but is too bulky and restrictive for active athletic use.
U.S. Pat. No. 4,796,303 to Atwater is for a knee protector pad including an elastic sleeve to maintain the pad in its intended position. The pad accomodates various sizes of legs by virtue of the elastic sleeve. Therefore, such a pad would be too tight for a large leg and too loose for a small leg.
U.S. Pat. No. 4,272,850 to Rule is for a thick foam sleeve that fits around the knee and has transverse slits extending part way through the sleeve to the outside surface to provide more freedom for flexing the knee joint. The sleeve entirely covers the knee joint so that the joint would be overheated during active use.
Other disclosures are directed toward composite structures that are intended to confer certain characteristics on pads used in various situations related to protection of the body. U.S. Pat. No. 5,168,576 to Krent et al is for protective body padding comprising a plurality of foam modules interconnected by a membrane having a plurality of perforations extending therethrough and a matrix of interconnecting air channels. Hardness to resist impact is conferred by having an outer layer of the foam being a higher density than the interior part of the foam This construction would not provide the wear resistance to abrasion or tensile strength to resist tearing that is an object of the guard of the present invention.
U.S. Pat. No. 4,991,230 to Vacanti discloses shock absorbing body pads including inflated compartments that communicate with the ambient environment through a plurality of ducts. The impervious construction of the pads mitigate against evaporation of moisture from the skin adjacent to the pads.
U.S. Pat. No. 4,642,814 to Godfrey discloses non metallic springs encapsulated in a vinyl type material. This complex construction does not permit "breathing" of the skin such as desired for elimination of heat.
U.S. Pat. No. 4,926,503 to Wingo discloses a pad comprising two layers of foam having two different densities. This construction does not provide the tensile strength required to bind various sections of a knee guard together which is an object of the present invention.
None of the foregoing disclosures combine the degree of tensile strength, resistance to wear and tear, breathability, nor accomodation to a variety of situations such as use for either recreational skating or stunt skating which is an object of the present invention.